Generalized pruritus without primary lesions. Differential diagnosis and approach to treatment

A 65-year-old man presented with recurrent generalized pruritus and excoriations of many years' duration. He had been treated with antihistamines, topical corticosteroids, and antibiotics for secondary wound infections, but improvement was only temporary. He had also been hospitalized for leg ulcers complicated by cellulitis. Examination revealed multiple oval and linear red papules and nodules measuring 0.5 to 2 cm in diameter. Some of the lesions were eroded and had a central crater and yellowish crust. The patient also had hypopigmented linear scars localized to the posterior scalp, neck, upper back, chest, abdomen, arms, and legs with sparing of the middle and lower back (figures 1 and 2). An ulcer measuring 1.5 x 2 cm that was surrounded by indurated skin was present on the medial aspect of his right ankle. The ulcer was partially covered by yellow exudate. There was no evidence of cellulitis. Liver enzyme, serum creatinine, and thyrotropin levels, as well as a chest roentgenogram, were normal. Wound cultures for bacteria and fungi were nonsignificant. A punch biopsy from a representative lesion showed an abrupt epidermal defect with sparse superficial lymphocytic infiltrate in the dermis. The patient was admitted to the hospital to isolate him from his home environment. He received a 10-day course of systemic cephalexin, topical clobetasol propionate ointment for the affected skin areas, and oral hydroxyzine for pruritus. Ultraviolet light therapy was instituted once daily and was to continue for 2 months. His lesions had improved moderately by the time he was discharged from the hospital. On follow-up 2 weeks later, his lesions were flat and had resulted in hypopigmented scars. Three months later, however, he had persistent, intense pruritus, and new excoriations had developed on his forearms and back. He improved after receiving treatment with oral doxepin hydrochloride.